PCB and Cooling System
NVIDIA’s policy regarding its top-end graphics cards is rather strict. The card manufacturers receive all GeForce 7800 GTX ready-made, so the difference between two such cards may only be in their cooling systems or, more often, in the picture on the cap of the reference cooler. The rules are more flexible for products from lower categories: the graphics card manufacturer is permitted to use a PCB design other than the reference one or at least to buy PCBs rather than ready-made products. The examples are the ASUS Extreme N7800GT with a blue-colored PCB and the unique ASUS Extreme N6600GT Silencer that has twice the memory amount of the ordinary GeForce 6600 GT and also features a noiseless cooling solution.
ATI Technologies currently administers the same strict policy of selling to its partners only ready-made top-end solutions, not allowing any experiments with the PCB design. You may recall that non-standard PCBs were permitted earlier – see our review of the masterpiece of a graphics card, the ASUS RADEON 9800 XT/TVD model. So there are no original solutions with ATI’s GPUs on the market, but the end-user at least may rest assured that his/her graphics card is the same quality and as reliable as any other.
Sapphire Technologies is the main partner of ATI in graphics card manufacture and it’s on Sapphire’s facilities that the bulk of ATI’s graphics cards are made, except for engineering samples. It is not a wonder then that the Sapphire RADEON X1800 XL is an exact replica of the reference card. It is itself the reference card!
The Sapphire card differs from the engineering sample of the RADEON X1800 XL we described in an earlier review in one point only: the sticker on the cooler’s cap shows you the same alien as is depicted on the card’s package, rather than the red-haired sword-wielding Ruby.
Otherwise, this is the same RADEON X1800 XL with a compact, yet quite efficient cooling system based on two U-shaped heat pipes and a thin-ribbed copper heatsink. This single-slot cooler successfully copes with the cooling of an R520 chip clocked at 500MHz as well as of eight chips of GDDR3 memory clocked at 500 (1000) MHz. These are still Samsung K4J55323QG-BC14 chips in 136-pin packaging, so we can expect some hefty overclocking gain as this memory is rated to work at 700 (1400) MHz. We have little hope for good GPU overclocking as the RADEON X1800 XL uses R520 chips of an early revision that are not capable of working at frequencies above 550MHz. Anyway, we’ll check this out shortly. To end this section of the review we just want to add that the reviewed graphics card is equipped with a Rage Theater chip and, accordingly, can capture and digitize video from analog video sources.